title: "Megavirales", a proposed new order for eukaryotic nucleocytoplasmic large DNA viruses.
abstract: The nucleocytoplasmic large DNA viruses (NCLDVs) comprise a monophyletic group of viruses that infect animals and diverse unicellular eukaryotes. The NCLDV group includes the families Poxviridae, Asfarviridae, Iridoviridae, Ascoviridae, Phycodnaviridae, Mimiviridae and the proposed family "Marseilleviridae". The family Mimiviridae includes the largest known viruses, with genomes in excess of one megabase, whereas the genome size in the other NCLDV families varies from 100 to 400 kilobase pairs. Most of the NCLDVs replicate in the cytoplasm of infected cells, within so-called virus factories. The NCLDVs share a common ancient origin, as demonstrated by evolutionary reconstructions that trace approximately 50 genes encoding key proteins involved in viral replication and virion formation to the last common ancestor of all these viruses. Taken together, these characteristics lead us to propose assigning an official taxonomic rank to the NCLDVs as the order "Megavirales", in reference to the large size of the virions and genomes of these viruses.
authors.affiliation: Unité des Rickettsies, URMITE UMR CNRS 7278 IRD 198 INSERM U1095, Facultés de Médecine et de Pharmacie, IHU Méditerranée Infection, Aix-Marseille Université, 27 Boulevard Jean Moulin, 13385, Marseille Cedex 05, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Colson
authors.forename: Xavier
authors.initials: X
authors.lastname: De Lamballerie
authors.forename: Natalya
authors.initials: N
authors.lastname: Yutin
authors.forename: Sassan
authors.initials: S
authors.lastname: Asgari
authors.forename: Yves
authors.initials: Y
authors.lastname: Bigot
authors.forename: Dennis K
authors.initials: DK
authors.lastname: Bideshi
authors.forename: Xiao-Wen
authors.initials: XW
authors.lastname: Cheng
authors.forename: Brian A
authors.initials: BA
authors.lastname: Federici
authors.forename: James L
authors.initials: JL
authors.lastname: Van Etten
authors.forename: Eugene V
authors.initials: EV
authors.lastname: Koonin
authors.forename: Bernard
authors.initials: B
authors.lastname: La Scola
authors.forename: Didier
authors.initials: D
authors.lastname: Raoult
mesh_terms: D004267:DNA Viruses / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D004279:DNA, Viral / Q000235:genetics; D056890:Eukaryota / Q000821:virology*; D019143:Evolution, Molecular; D009626:Terminology as Topic
chemical_list: D004279:DNA, Viral